Resonant conversion control method and device with a very low standby power consumption

Abstract

A resonant conversion control device with a very low standby power consumption has an AC-to-DC conversion unit, a DC-to-DC conversion unit, a DC-to-DC conversion control unit, and a standby mode control unit. The resonant conversion control device effectively makes use of the low switching loss characteristic of a resonant conversion device, and uses the output voltage for judgement of the system operation mode. The resonant conversion control device can control the action statuses of the AC-to-DC conversion unit and the DC-to-DC conversion unit to lower effectively the power consumption under the standby mode. Therefore, the resonant conversion control device can solve the problem of a higher standby power consumption of conventional switching power supplies and meet the requirements of future standby power standards.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the invention [0002] The present invention relates to a conversion control method and device with a very low standby power consumption and, more particularly, to a conversion control method and device capable of achieving a higher conversion efficiency and a very low standby power consumption under any load conditions. [0003] 2. Description of Related Art [0004] Owing to gradual exhaustion of usable energy, the exploitation of various kinds of energies and restriction of energy use are now becoming a common consensus worldwide. Well-developed countries like the US, Europe, and Japan have made appropriate energy policies for energy use. The standards of power consumption in the standby mode (i.e., green power) of electrical products are generally set below 0.5-1 watt to avoid excessive power consumption when electrical products are standing by. Manufacturers of relevant electronic products have developed appropriate products (power-savin...

AI Technical Summary

Benefits of technology

"The present invention provides a resonant conversion control method and device with a very low standby power consumption to enhance conversion efficiency and solve standby power consumption problems of conventional switching power supplies. The method and device adjust the switching frequency of the resonant conversion device based on the frequency response and load condition of the resonant components, and make use of the energy conversion characteristic of the resonant conversion device to achieve zero-voltage switching. A synchronous rectifying circuit can be used in the DC-to-DC conversion unit to enhance the whole conversion efficiency. Hysteresis comparison control is adopted to control the actions of the resonant conversion device at the appropriate time (under a very light load or no load). The standby mode control unit receives the second DC voltage output by the DC-to-DC conversion unit and adjusts the frequency of the control signal of the power transistor of the DC-to-DC conversion unit to control the circuit actions. The system operation is based on the detection of the output voltage, and three voltage thresholds are used to determine the present system load situation. The method and device can effectively reduce the switching power loss under normal operation, lower the standby power consumption, and achieve higher conversion efficiency."

Problems solved by technology

Power consumption also accompanies use of the snubber.

Moreover, a common flyback converter cannot accomplish soft-switching without using special control or auxiliary switches.

Power consumption also accompanies hard-switching of the power transistor.

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